122508

Appears in sequences

• a(n) = binomial(n,0) - binomial(n,2) + binomial(n,4).at n=43A058923
• Triangle T(n,k) (n >= 3, k = 1..n-2) read by rows giving number of abstract order types of configurations of n points in n-k dimensions.at n=20A063853
• Number of abstract order types of configurations of n points in 2 dimensions.at n=5A063854
• Number of (n+6)X7 0..1 matrices with each 7X7 subblock idempotent.at n=3A224581
• Number of (n+6)X10 0..1 matrices with each 7X7 subblock idempotent.at n=0A224584
• T(n,k)=Number of (n+6)X(k+6) 0..1 matrices with each 7X7 subblock idempotent.at n=6A224588
• T(n,k)=Number of (n+6)X(k+6) 0..1 matrices with each 7X7 subblock idempotent.at n=9A224588